1. Field of the Invention
This invention relates to an image recording apparatus and an image recording method to be suitably used for copying and recording a so-called edge-lit type hologram or holographic stereogram. The present invention also relates to a recording medium carrying an edge-lit type hologram or holographic stereogram copied and recorded thereon.
2. Prior Art
Techniques utilizing a holographic stereogram for recording a three-dimensional image on a recording medium have been known. A holographic stereogram is prepared by using a large number of images obtained by sequentially shooting a same object from so many viewing points and sequentially recording them as originals on a single hologram recording medium.
Of various known types of holographic stereogram, there is one with which the viewing points are shifted only horizontally to obtain a large numeral of images that are differentiated from each other by parallax, which are then sequentially recorded on a single hologram recording medium as so many strip-shaped element holograms.
Referring to FIG. 1 of the accompanying drawings, a plurality of originals 201a through 201e obtained by sequentially shooting an object 200 from so many viewing points that are shifted only horizontally from each other are then sequentially recorded on a hologram recording medium 202 as so many strip-shaped element holograms.
Thus, with such a holographic stereogram, since the images obtained by sequentially shooting the object from so many viewing points that are shifted only horizontally from each other are sequentially recorded on a recording medium as so many strip-shaped element holograms, the two eyes of the viewer watching the holographic stereogram will catch respective two-dimensional images that are slightly different from each other. Then, the viewer will be made to feel a parallax and see a three-dimensional image due to the principle of stereogram.
Meanwhile, when reproducing a holographic stereogram prepared in a manner as described above, the light source to be used for reproducing a three-dimensional image and the holographic stereogram to be reproduced are normally separated from each other within a space. In other words, a relatively large space is required to reproduce a holographic stereogram. Additionally, the holographic stereogram to be reproduced and the light source to be used for reproducing the holographic stereogram have to be arranged in such a way that they satisfy certain predetermined requirements in order to reproduce the holographic stereogram under optimal conditions. Thus, cumbersome operations are inevitably involved there.
As an attempt for dissolving the above identified problems and reproducing a three-dimensional image without difficulty, there has been proposed an edge-lit type holographic stereogram using a recording medium bonded to a transparent light-introducing block by way of an index-matching solution so that an image may be recorded there by introducing reference light through an end face of the light-introducing block and the recorded image may be reproduced by causing light to strike the end face of the light-introducing block for image reproduction.
With such an edge-lit type holographic stereogram, the light source for emitting light for image reproduction can be integrated with the light-introducing block to down-size the reproduction optical system and always carry out the image reproduction operation under optimal conditions. Additionally, such an edge-lit type holographic stereogram provides an advantage that the recorded image cannot be reproduced with light entering from the outside of the light-introducing block because of a large angle of incidence of light used for image reproduction.
Thus, because of the above identified various advantages, edge-lit type holographic stereograms may possibly find applications in ordinary image display apparatus. Then, a large number of holographic stereograms carrying same and identical image information may have to be prepared.
Thus, it is an object of the present invention to provide an image recording apparatus and an image recording method to be suitably used for preparing a large number of edge-lit type holograms or holographic stereograms in a simple manner by copying. Another object of the present invention is to provide a recording medium carrying an edge-lit type hologram or holographic stereogram copied and recorded thereon.
In an aspect of the invention, there is provided an image recording apparatus for copying and recording the image information recorded on a master such as a hologram or a holographic stereogram carrying thereon the image information recorded by using interference of object light and reference light on some other recording material, said image recording apparatus comprising:
an exposure processing section for causing reading light for reproducing the image information recorded on said master to strike an end face of said optical member, said recording material being laid on said master, said master and said recording material being optically held in contact with a light-transmitting block-shaped optical member;
the reproduction light from said master reproduced by said reading light being caused to interfere with said reading light in said recording material to copy and record the image information recorded on said master on said recording material.
With an image recording apparatus according to the invention and having a configuration as described above, the recording material is laid on the master in the exposure processing section and optically brought into with the light-transmitting block-shaped optical member. Then, reading light for reproducing the image information recorded on the master is made to strike an end face of the optical member. Note that, in this patent document, a block refers to a rigid and solid block having a height greater than an ordinary picture film.
The reading light striking an end face of the optical member is then modulated as a function of the image information recorded on the master as it irradiates the master to become reproduction light. Then, as the reproduction light from the master and said reading light interfere with each other in said recording material, the image information recorded on the master is copied and recorded on the recording material.
With an image recording apparatus according to the invention and having a configuration as described above, the image information recorded on the master can be copied and recorded with ease simply by laying the recording material on the master, bringing them into optically in contact with the block-shaped optical member and making reading light for reproducing the image information recorded on the master to strike an end face of the optical member.
Preferably, said optical member is provided at least in part thereof other than the portion to be optically held in contact with said master and said recording material and the end face to be stricken by said reading light with a light absorption means for absorbing light. With the provision of such a light absorption means, the reading light entering the optical member is prevented from being unnecessarily reflected inside said optical member so that the operation of copying and recording the image information can be carried out optimally.
In another aspect of the invention, there is provided an image recording method for copying and recording the image information recorded on a master such as a hologram or a holographic stereogram carrying thereon the image information recorded by using interference of object light and reference light on some other recording material, said image recording method comprising:
causing reading light for reproducing the image information recorded on said master to strike an end face of said optical member, said recording material being laid on said master, said master and said recording material being optically held in contact with a light-transmitting block-shaped optical member;
causing the reproduction light from said master reproduced by said reading light to interfere with said reading light in said recording material to copy and record the image information recorded on said master on said recording material.
With an image recording method according to the invention, the image information recorded on the master can be copied and recorded with ease simply by laying the recording material on the master, bringing them into optically in contact with the block-shaped optical member and causing reading light for reproducing the image information recorded on the master to strike an end face of the optical member.
Preferably, said optical member is provided at least in part thereof other than the portion to be optically held in contact with said master and said recording material and the end face to be stricken by said reading light with a light absorption means for absorbing light. With the provision of such a light absorption means, the reading light entering the optical member is prevented from being unnecessarily reflected inside said optical member so that the operation of copying and recording the image information can be carried out optimally.
In still another aspect of the invention, there is provided a recording medium carrying image information copied and recorded by using a master such as a hologram or a holographic stereogram carrying thereon the image information recorded by using interference of object light and reference light on some other recording material;
said image information recorded on said master being copied and recorded as interference fringes of the reproduction light from said master reproduced by reading light and said reading light by causing said reading light for reproducing the image information recorded on said master to strike an end face of said optical member, said recording material being laid on said master, said master and said recording material being optically held in contact with a light-transmitting block-shaped optical member.
In a recording medium according to the invention, the image information recorded on the master is copied and recorded with ease simply by laying the recording material on the master, bringing them into optically in contact with the block-shaped optical member and causing reading light for reproducing the image information recorded on the master to strike an end face of the optical member.
Thus, with an image recording apparatus according to the invention, an edge-lit type hologram or holographic stereogram can be prepared with ease because the image information recorded on a master can be copied and recorded on a recording material simply by laying the recording material on the master in the exposure processing section, bringing them into optically in contact with the block-shaped optical member and causing reading light for reproducing the image information recorded on the master to strike an end face of the optical member.
Similarly, with an image recording method according to the invention, an edge-lit type hologram or holographic stereogram can be prepared with ease because the image information recorded on a master can be copied and recorded on a recording material simply by laying the recording material on the master, bringing them into optically in contact with the block-shaped optical member and causing reading light for reproducing the image information recorded on the master to strike an end face of the optical member.
Finally, with a recording medium according to the invention, the image information recorded on the master is copied and recorded with ease simply by laying the recording material on the master, bringing them into optically in contact with the block-shaped optical member and causing reading light for reproducing the image information recorded on the master to strike an end face of the optical member. Such a recording medium can be used for an edge-lit type hologram or holographic stereogram.